In a wireless communication system, a terminal detects a signal quality of a neighboring cell using a carrier according to information of the carrier sent from network side. For a carrier aggregation system such as a long-term evolution advance (LTE-A) system, etc., a terminal may have multiple carriers serving the terminal at the same time. Carrier aggregation under a base station is called an aggregation cell. When an aggregation cell provides a service for a terminal, the terminal can simultaneously use multiple uplink and downlink carriers for data transmission. If a radio link failure occurs on only a part of carriers (uplink and/or downlink), the terminal can still communicate with the base station through other carriers without failure. Only when radio link failures occur on all carriers (downlink and/or uplink), the terminal determines that the radio link fails and initiates a Radio Resource Control (RRC) connection reestablishment process to resume a signaling connection with the base station. In a current discussion of a new radio system, for an RLC entity, if a group of cells configured for a corresponding logical channel are all secondary cells, then when a certain RLC SDU of AM RLC is retransmitted up to a maximum number of times, RRC reconfiguration may not be triggered, but only the event that retransmission reaches the maximum number of times needs to be reported, thus reducing impact of reconfiguration on a terminal. However, there is no discussion on how to configure an RLC entity accordingly so far.